How to unload shapefiles properly?

I want to move a shapefile into another directory while the application is still running.

After removing the shapefile from the map the runtime still holds a file lock onto the shapefile so the move operation fails. After some investigation I found out this problem only occurs if the map is associated to a mapview. But then even kicking the mapview out of the visual tree does not break the lock.

Is there some kind of Unload or Dispose method that I'm not aware of or is this a bug?

Remark: I'm using the latest version of the ArcGIS Runtime for .NET (100.2.1)